Auxiliary yarn tensioning means



Feb. 2, 154 c. A. HEPP AUXILIARY YARN TENSIONING MEANS Filed Aug. 14, 1951 FIG.2

Patented Feb. 2, 1954 U TL'EED? EJS Carlos At Heme,- Englewoodi. N: J.,. ass-ignon to Alfred Hofinann: &; C02, West New York; N. .L,

a corporation Application- August 14, 1951 SeriatNo. 2413832 iicclaimsi- 11 This invention relates to" auxiliary; yarn tensioning means for warp knittingrnacliines.

The problem of yarn'tensioning in Warp knitting machines such as. the high speed tricot and Simplex types; has" been" considered at length" and a: number of patents have been granted in this field" including 23941.61; 2,395,807; 2,397,663 and 2,521,218; a11 assigned to the assignee of' the. instant application; Such patents are primarily directed. to improvements inthe control of the yarn supply through means for driving and braking. the reel shafts which carry the yarn reels, so as to control thefiow of yarn in accordance. With the knitting requirement.

More particularly, machines described; inthe above. mentioned patents. include a yarn guide rod. mounted on rock. arms which. are. resiliently urged inone direction. by suitable spring .me-ans, the sheet of yarns moving. over. the guide. rod to the knitting, elements and being. tensioned during the knitting operation by the. spring means, in conjunction with braking means actuated for controlling. the rotation. of the reel shaft.

It has been foundhowever; that. with such arrangements, the quality of the. knitted. fabric isvariable due to, variations in. yarn tension, despite the: provisions for tensioning the yarns-as described above. is compel-led to follow certain. motions. of. the knitting elements; whichare'inno way related to the determination of. the yarn flowrequire-.- ment. As a result, the upand. down movement of the yarn guide rod, particularly in high .speed machines, produces excessivemotions which are transmitted to the yarns, causing the sameto flutter in their passage between: the guide rod and the knitting elements: In addition, excessive guide rod motion may frequently beresponsible for yarn breakage" due toza resultantzjerkingac.- tion. in respect to: the :yarns;

Accordingly, an ohjectoi this invention is-to provide in Warp. knitting machines having conventional resilient yarn tensioning means; aux iliary yarn tensioning means. adapted. to-suh1- stantially reduce. the up" and down motionloi the main yarn tensioning: means; and; thereby materially reduce: the fluttering and. jerking, of the yarns.

A further object of this invention :is: torprovide auxiliary yarn tensioning' means which maybe readily attached. to conventional warp; knitting machines without: material. modification; of J the same, yet: ada-ptedi iorz' operation: with". the; main...

(Dbviousl-y; the yarn guiderod yarn tensioning means of. the machine; where by to render more efiective: the usual. braking devices associated with the yarn reels: or: the combination braking and Iyarn v reel l driveimechainisms found irr-sucli machines:

Another" object of this invention is te provide warp. k-nitting machines; auxiliary yarn tensi'on-ing means adapted to be-locate'd' in a posittion suciitliat the normal" flow ot='yarn to'the main yarn tensiening means isdiverted; whereby theauxiliary 'tensioning means is adapted to b'eeomeoperative before the" main yarn tensioning means duringvarious phases of "yarn movement-to the knitting elements; thereby materially reducing the up and down movement of the-main yarn-tensionihg means.

Other objects of this invention will in part be obvious" and in" part hereinafter pointed out.

Theinvention accordingly-consists in the combination of elementsa-nd arrangement of parts which will be exemplified in the constructions hereinafter described.

In the'drawings',

Fig: 1 is-a side elevational viewof' the yarn tensioningimeans" embodying the invention; with parts *in' section;

Fig; 2 is" a top' plan" view" thereof; and" Fig.3 is asideelevational view of 21;."YZLI'I1" ten"- sioning means embodying. the invention. and illustrating, a modification thereof:

Referring in" detail to the drawing, and particularly tolii'g, 1, it"designates'a fulcrum bar or rockaxleoflaconventional warp knitting machine, .such bar. extending longitudinally of Tthe machine andsuitably mounted in the frame of the. machine,..in a. manner well. known in the art; The bar It may also be'arrangedffor rocking movement ..so.-as to providemeansfor. actuating brakes. or..reel1 driving means, in a manner knowniini the art;

Themainyarn. tensioning. means comprises a. plurality of." similar, .suii'iablyv spaced. arms.- H disposed.at.right.angles to.tliev bar. it. and suit.- ably.- fixed. at. their. inner. enatsto. saidbar. At the outer ends.-.of; the arms. I], there isflfixed the longitudinally, extending yarn guide. tension bar. l znvhich is parallelnto. Ill- On the opposite side 0t bar I0 is provided-a longitudinally extending steady rod l3, suitably fixed: onthe frame. of themachineand providingguide means fardirecting theisheet. of, yarniy: coming. from the; reel, notsshowm. to-the guideban i2.,. the yarns. then. moving dovmwardly to. the; knitting elements,,. not: shown-.1,

Ass in: conventional; Warn; knittingmachines,

arms II and guide bar I2 are urged in an upward direction by suitably located spring means, in a manner known in the art and typically shown in Patent 2,521,218. Thus, the moving sheet of yarns are tensioned with the spring means contracting and expanding in accordance with the yarn demand of the knitting elements. It follows that the arms 5 i and the guide bar l2 must execute repeated up and down movements in response to the variation in tension of the moving yarns and the rate of such movement is determined by the speed of the machine.

Means is provided for substantially reducing the up and down movement of the main yarn tensioning means. To this end there is provided auxiliary yarn guide tension means. Such auxiliary means comprises a plurality of similar, resilient elements I l. Each element M, which may be made of thin, strip metal, includes an intermediate, preferably curved portion 5 which may be complementary to the curvature of bar l and is adapted to freely straddle the same. Extending from either side of portion [5, are upwardly inclined arm portions it, ll. The resilient elements hi are suitably spaced on bar ill and have the outer ends of arm portions 18, ll, respectively interconnected by auxiliary guide rods l8, 19 which extend parallel to main guide bar l2. As shown in Fig. 1, the arm portions [6, I! may be of equal length and shorter than arms H. Furthermore, arm portions l5, ll are inclined at an angle such that the auxiliary guide rods l 8, l9 are normally located above the axis of the bars l0, l2.

It will be apparent from a consideration of Fig. 1, that the sheet of yarns y, which would normally travel in a path indicated by the dot and dash lines a, are now diverted to a new path indicated by the dotted lines b.

The spring elements I 4 show a lesser resistance to a given force than the spring means, not shown, which urges the arms I! upwardly. Accordingly, with normal operation of the knitting machine, take up in the slack of the yarns 1/ moving to the knitting elements, will in a large part be accomplished by means of the auxiliary yarn guide tension means. In the event that yarn tension attains a value such that the arm portions It, ii are biased to a point where the rod l8 is in the same horizontal plane as the guide bar 12, then any increase in yarn tension beyond said value, will cause guide bar I2 to move downwardly. In such event, arms I I will rock the bar $2 in a manner known in the art and may thus actuate brake means or reel driving means, as more specifically described in Patent 2,521,218. f i

It follows, that the up and down movement of the main yarn guide tensioning means will be materially reduced at all speeds of the knitting machine. Furthermore, it has been found that with the auxiliary yarn tensioning means, as shown herein, flutter of the yarns is greatly reduced and the brake and reel drive mechanisms which may be associated with the fulcrum bar l0, operate with greater efiioiency.

In warp knitting machines having double yarn guide tension bars l2, i2a, mounted on oppositely extending arms ll, Ha, respectively, as shown in Fig. 3, the auxiliary yarn tensioning means comprises strip spring elements Ma. Such elements include an intermediate curved portion l5a which loosely straddles the underside of the bar l6 and is kept in place by straps 20. The arm portions I 8a, Ila extend from either side of portion 15a and are inclined downwardly. Guide rods 18a, l9a interconnect the outer ends of arm portions 16a, Ila, respectively. As shown in the figure, rods 18a, 19a are normally located in a horizontal plane below the horizontal plane containing guide bars [2, I2a. In this manner, the path of yarns y is again diverted or displaced from the normal whereby the spring elements Ma may function independently of the main yarn tensioning means until the yarn tension exceeds a given value when the main yarn tensioning means will operate as described above.

It will be apparent that the auxiliary yarn tensioning means described above, may be readily mounted on the fulcrum bar of a conventional warp knitting machine, or upon any other suitable support forming a part of the machine.

The resilient capacity of one or more of the spring elements I l, Ma, may be modified by varying the transverse section or longitudinal extent thereof. The guide rods l8, l9; lila, lea, may be of light, somewhat flexible material, so that the same may exhibit varying response to different yarn tensions along the length of the machine. Thus, the selvage portions of the machine may have reduced tension responses as compared to intermediate portions of the machine.

While the auxiliary yarn tensioning means described above includes resilient arm portions extending from either side of the fulcrum bar or other suitable support, it is understood that the auxiliary yarn tensioning means may have but single arm portions extending from one side only of the fulcrum bar or other suitable support. In such case, the arm portions may be fixed to the support.

As various possible embodiments might be made of the above described invention, and as various changes might be made in the embodiments set forth, it is understood that all matter herein set forth or shown in the drawings, is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim as new and desire to protect by Letters Patent:

1. In a warp knitting machine, the combination of a movable fulcrum member, a yarn guide tension bar on said movable member, and auxiliary yarn tensioning means mounted on said fulcrum member and including a resiliently mounted auxiliary yarn guide tension bar having an axis normally located in a plane parallel to a plane containing the axes of said movable member and first mentioned yarn guide tension.

on at least one side of said movable member being interconnected by an auxiliary guide bar extending parallel to said first mentioned guide bar, said auxiliary guide bar being located in a horizontal plane spaced from and parallel to a horizontal plane containing said first mentioned 7 guide bar.

3. In a warp knitting machine as in claim 2 wherein said auxiliary guide bar is located above a horizontal plane containing said movable member.

4. In a warp knitting machine as in claim 2 wherein said auxiliary guide bar is located below a horizontal plane containing said movable membar.

5. In a warp knitting machine, an elongated fulcrum support, main yarn guide tensioning means including a main guide bar extending parallel to and to one side of said support, auxiliary yarn guide tensioning means including an auxiliary guide bar located between said main guide bar and said support and parallel thereto, and resilient means for normally positioning said auxiliary guide bar to one side of a plane containing said main guide bar and support.

6. In a Warp knitting machine as in claim 5, wherein said auxiliary guide bar is fixed to said support.

'7. In a warp knitting machine as in claim 5 wherein said resilient means includes a plurality of members located in spaced relation, said members being of variable resilience.

8. In a warp knitting machine, a pair of adjacent movable yarn guide members, resilient means for mounting one of said members and operative in response to at least a predetermined yarn tension to move said one member, resilient means for mounting the other of said members and operative in response to yarn tensions less than said predetermined tension to move said other mem- 6 her, said other member being movable in response to said predetermined yarn tension to a position relative to said one member whereby said pair of members are conjointly movable in response to said predetermined yarn tension.

9. In a warp knitting machine, a resiliently mounted movable member for guiding yarns in a predetermined path, a second resiliently mounted movable guide member adjacent said first mentioned member for displacing said yarns from said path in response to yarn tensions less than a predetermined tension, said second guide memher being movable in response to said predetermined yarn tension to a position relative to said first mentioned member whereby said yarn is restored to said predetermined path, and said first and second members being conjointly movable in response to yarn tensions greater than said predetermined tension.

CARLOS A. HEPP.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,172,764 Burson Feb. 22, 1916 1,623,608 Wetzel Apr. 5, 1927 2,022,834 Welch et a1 Dec. 3, 1935 2,308,430 Bolden et al. Jan. 12, 1943 2,442,796 Young June 8, 1948 2,451,499 Lambach Oct. 19, 1948 

